I often will take a 7 1/2' 4x leader and add 18" of 5x tippet to give me a 9' leader. That way as I change flies and cut back, I'll know where my tippet starts. I have also started experimenting with tying a tippet ring to the end of the leader and tying my tippet to the ring. The jury is still out on that, but I have used that system once already this year and it seems to work okay.